File Upload problem

Hi,

I have installed uni cpo on our 3rd website.
The page has file upload functionality.

The settings are set to upload to a dropbox (I have pasted the access token generated by drop box).

When I upload the file, it says it is uploaded. However, I cannot see it in the dropbox account. When I add to the basket, it doesn’t show the name of the file that has been uploaded (normally it would show the target drop box location).

I have created a brand new upload item, thinking the original one may be corrupt.
However, this doesn’t upload anything either.

Is there any method I can use to find out why this is happening?

TIA